The Spice Girls may have coined the term "girl power", but Franco-American painter-sculptor Niki de Saint Phalle was practising it long before they were born.

Saint Phalle's version, "Nana Power", takes its name from the French word nana, meaning "chick". It's the title of a show-stopping image of the artist in which she points a gun at the camera, playing to the public's perception of her as a woman who muscled her way into a male-dominated art world.

Nana Power (1970) kicks off a major retrospective of Saint Phalle's work at Tate Liverpool. The first UK exhibition of the artist's work since her death in 2002, it is a glorious revelation. Saint Phalle is often dismissed as "playful", despite her collaborations with many of the art world's leading figures such as Jasper Johns and Robert Rauschenberg and a vast legacy of works exhibited in some of the world's most high-profile institutions.

Yet, as the vibrant examples selected from each of the different phases of her career attest, Saint Phalle could also be boldly provocative.

Like the Mexican artist Frida Kahlo, Saint Phalle was self-taught. This is apparent from the childlike quality of her early works - the free-flowing lines of the chaotically colourful La Fête (c1953-55) and the freedom from concern for perspective or proportional relationships.

Also in common with Kahlo, Saint Phalle poured a rage against injustice into her work. How could anyone not feel the anger of La Mort du patriarche (1962/72), the accusatory collage of tanks, toy soldiers and planes that the artist began during the last year of Algeria's desperate fight for independence against the occupying French?

It has been argued that part of what makes the work of Kahlo and Tracey Emin so intriguing is that it is shockingly autobiographical. Saint Phalle also endured her fair share of traumas, which she exorcised through her work. Abused by her aristocratic French father, she suffered a nervous breakdown in 1953, which she attempted to alleviate by making art.

Her work begins innocently enough with pieces such as the aforementioned La Fête, but it develops into stomach-turning collages of dolls' limbs, glass eyes and razor blades in the appropriately named Paysage de la mort (1960). Later in life, Saint Phalle tackled the abuse she suffered head-on in the disturbing film Daddy (1973). But the exuberant nature of many of the works on display in this exhibition suggests that the lows of the artist's life were balanced by wonderful highs.

Saint Phalle exploded onto the international art scene in 1961 with her Tirs (Shooting Paintings). The artist secreted plastic bags filled with paint behind paintings, and sculptures; the bags burst when the works were shot by a gun held by Saint Phalle or other participants. The first "shooting" took place in the artist's studio in Paris. Among others watching the event was Pierre Restany, founder of the Nouveaux Réalistes. On the strength of the four works created, Restany invited Saint Phalle to join them.

The most interesting Tir on display is Hommage to Bob Rauschenberg (Shot by Rauschenberg, 1961). An assemblage was created by Saint Phalle to resemble a Rauschenberg piece, then the artist himself was invited to "destroy" his "own" work and "begin" another by shooting it, causing the pockets of dark paint to explode.

The Tirs caused a sensation and established Saint Phalle as part of the avant-garde. The artist whose beautiful face had graced the covers of Vogue and Life magazine in her former career as a model, revelled in her new-found success. She had a white jumpsuit made for her performances, which she wore paired with trademark black boots.

As the 1960s progressed, Saint Phalle's attention became increasingly focused on the female figure. A room is devoted to the archetypal stereotype of the woman as bride, which Saint Phalle explored time and again, and to her Nanas - the giant, sometimes tumbling, figurative sculptures which are perhaps her best-loved works. Inspired by the pregnancy of Saint Phalle's friend Clarice Rivers, the voluptuous creations have become synonymous with fertility and maternity.

The most intriguing Nana is Venus (1964). It's not as large or as bold as others, but its "wormy" face, made of coiled wool, and the motifs of grapes, roses and horses which the artist has woven into its wire-mesh body (themes repeated throughout Saint Phalle's work), are strangely compelling.

Some of Saint Phalle's late works feel purely decorative, lacking the disquieting power of her earlier paintings and sculptures - but to write off the artist as simply "playful" is unfair. It's about time Saint Phalle was given her due by art history and recognised as the daring groundbreaker she was.